CurtPalme.com Home Theater Forum

JohnAd · Joined: 12 Mar 2012 Posts: 21

After after pretty good run my barco 1208 with 9inch tubes seems to be dying Crying or Very sad

I was using it yesterday when the screen went black for a bit, I smelt the distinctive smell of burnt out components and thought that must be it. It did come back on with nothing out of the red tube. A power cycle later and there is light coming off the red tube but there appears to be no discernible image looking back into it. If I put up the genlocked convergence pattern I can see the lines on the green and blue tubes but the red just looks evenly bright with only very faint lines visible and there is nothing on the screen if I select red only.

I've not really had to look properly inside my beast as it was put in place by Roland Brooks long ago and have no real feel for what I'm doing when I take the cover off.

So I could use some advice on the following:

Do these symptoms sound like an issue that is easy to fix?
Is there any further relatively simple diagnosis I can do?
Is there anyone left in London or the UK who fixes these things?

Thanks

John

winny · Posted: Sun Jun 28, 2015 8:30 pm Post subject:

Check your RGB input card (R7617481). Mine didn't have any red signal either, or extremely weak, until I replaced it. Unless you can smell what burnt in yours.

JohnAd · Joined: 12 Mar 2012 Posts: 21

I kind of assumed it wasn't the input card after checking the internally generated patterns had the same issue, is that a fair conclusion?

John

winny · Posted: Sun Jun 28, 2015 9:34 pm Post subject:

No, I had the same problem.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Thanks for that, what's best way of telling which board is which and which bits to open up? As I said I'm not very familiar with the innards.

John

**Curt Palme** · Posted: Sun Jun 28, 2015 9:42 pm Post subject:

Very easy to solve.. most likely. Smile

The problem is either one of the two video cards in the middle of the set, or more likely the CRT socket/video amp, which is on the back of each tube. All three are identical, and can be interchanged.

There's really no one left working on these except for me, but I'm selling 1208 parts off cheap.

Try swapping the red CRT socket/amp with the green or blue. The two connectors at the bottom are different sizes, so make sure the right one goes on the right connector.

If the problem moves to the other tube, then it's that video amp, and I've got lots here. if the problem stays, then it will be one of the video cards, but the CRT socket is far more likely to cause the problem. Here's the location of the video cards:

http://www.curtpalme.com/Barco1208_Layout2.shtm

(RGB switcher and quad decoder)

winny · Posted: Mon Jun 29, 2015 8:23 am Post subject:

Yes, if you smell something burning, the RGB input is unlikley. It looks like this: http://www.curtpalme.com/forum/viewtopic.php?p=395615#395615

Any luck swapping the neckboards?

JohnAd · Joined: 12 Mar 2012 Posts: 21

Thanks for the comments everybody, already feeling bolder and looking forward to getting more personal with my projector this evening.

John

**Curt Palme** · Posted: Mon Jun 29, 2015 2:54 pm Post subject:

the only caveat is to be careful not to bend the CRT pins as you're removing and installing the video amp. Not a lot of room back there to move. If you do bend a pin, don't panic, they take a lot of flexing before they break, I've bent some in half.. literally, and they haven't snapped... of course it's usually the bottom ones that bend, and sometimes you have to take the tube out to bend them back, so just be aware that they can bend.

winny · Posted: Mon Jun 29, 2015 2:59 pm Post subject:

And the high voltage that will kill you...

**Curt Palme** · Posted: Mon Jun 29, 2015 3:00 pm Post subject:

Nothing more than 800 volts on the CRT socket.. and that's with it turned on. that doesn't even give me a tickle.

(NO HV is present when the set is off!)

winny · Posted: Mon Jun 29, 2015 3:06 pm Post subject:

My point is - unplug it Smile

Even pros fail sometimes. I almost killed myself at work by forgetting to unplug the amplifier I was working with once.

JohnAd · Joined: 12 Mar 2012 Posts: 21

JohnAd · Joined: 12 Mar 2012 Posts: 21

So good news of sorts, swapping the neck boards fixes the red and moves the problem to the green. Looking at the board it looks like a burnt out resistor.

So off to Curt I go for a new neck board.

John

JohnAd · Joined: 12 Mar 2012 Posts: 21

While in the projector there was a quite spectacular amount of dust covering important looking stuff and probably not helping with the cooling. What's the best and safest way to clear the boards?

John

winny · Posted: Mon Jun 29, 2015 8:18 pm Post subject:

What part number on the neckboard? R followed by lots of digits.

Compressed air?

JohnAd · Joined: 12 Mar 2012 Posts: 21

The neck board is a R762292

Was thinking of using a compressed air can but sometimes it does seem to make things a bit too cold.

John

**Curt Palme** · Posted: Mon Jun 29, 2015 10:13 pm Post subject:

go nuts with the compressed air. I have a shop compressor that I regularly blow things out with.

winny · Posted: Tue Jun 30, 2015 8:11 am Post subject:

I have two neckboards from a 1208 which I have no use for but the number is different.

JohnAd · Joined: 12 Mar 2012 Posts: 21

winny

Thanks a lot for looking Thumbs Up

John